JPS5934970B2 - Cable fatigue test equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cable fatigue testing device.

In submarine oil production systems, equipment on the seabed and equipment on the ocean are connected through multi-node riser pipes, and various cables are housed within these riser pipes.

The node part is a universal joint 10 as shown in Figure 1.
It is curved so that it can bend freely.

The cables 12, 12' passing through the through hole 511 of this universal joint are not only bent but also twisted in accordance with the bending of the universal joint. Here, the bending is a combination of large bending due to direction reversal of the current and minute bending due to wave motion. 10 In addition, 12, 12
' is the same cable, 12 is the upright case, 12' is the bending angle of 700, 13 and 14 are the cable fixing points, and 15 is the riser pipe.

Whether or not cables can withstand these repeated bending (top bending, minute bending) and twisting is an important issue, and it can be said that appropriate testing equipment is required for this purpose. The present invention provides a cable fatigue testing device with a simple structure that meets the above objectives.The present invention will be explained below with reference to the drawings.

J Fig. 2 is an explanatory diagram of an embodiment of the cable fatigue testing device of the present invention, in which a twisting device 21 (arrow a indicates twisting) of a test cable 20, a self-propelled vehicle 22 for top-hanging, and the self-propelled vehicle The present device 25 is composed of a guide rail 23, a minute bending device 24, and a universal joint penetration simulating member 25.

This device moves in a two-dimensional manner, whereas the actual universal joint shown in FIG. 1 moves three-dimensionally.

In reality, the cable is twisted by the three-dimensional movement of the universal joint, but in this device, the upper end support point of the 30 cable can be rotated as shown by arrow a, giving equivalent twist to the cable. In addition, as a method of superimposing the top bending (arrow b) and minute bending (arrow c), the intended purpose 35 can be achieved by placing the minute bending device 24 on the top bending self-propelled vehicle 22. There is. In FIG. 2, twisting is applied by a gear mechanism consisting of gears 26 and 21, top ridges are applied by wheels, and minute bending is applied by a crank mechanism, but any mechanism may be used for the movement.

However, it is necessary to give repeated back and forth motion. In FIG. 2, there is a risk that the self-propelled vehicle for large bending may slip on the rail 23, but if the rails are mechanically engaged, for example, by a pinion ratter mechanism, no slipping will occur.

It is the frame 30 that mounts the above device. Further, by adjusting the twist angle, large bending angle, and small bending angle using the limit switch 28 or the like according to actual conditions, tests under all conditions can be performed with one device.

Note that arrow b indicates large bending, and arrow c indicates slight bending. The advantages of the cable fatigue test device of the present invention are: (1) Since the cable is twisted at the upper support point of the cable,
The planar device can simulate a riser pipe universal joint that moves three-dimensionally.

(2) Twisting angle and bending angle can be easily changed, so
Can accommodate a wide range of test conditions.

(3) Since twisting, large bending, and small bending can be applied simultaneously, it is possible to conduct tests that match the actual conditions.

etc.

As described above, the present invention makes an extremely large contribution as a test device for understanding the mechanical fatigue phenomenon of cables passing through a riser pipe universal joint.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of a universal joint of a riser pipe, and FIG. 2 is an explanatory diagram of an embodiment of the cable fatigue testing apparatus of the present invention. 10...Universal joint, 11...
...Through hole, 12, 12'...Cable, 1
3, 14... Cable fixing point, 15...
・Riser pipe, 20... Test cable, 21.
...Twisting device, 22...Self-propelled vehicle for large bending, 23...Guide rail, 24... ．．
Microbending device, 25...Universal joint penetration part simulating member, 26, 27...Gear, 28
...Limit switch (for large bending reversal), 30
······flame.

Claims (1)

[Claims] 1. A device for suspending cables and subjecting them to repeated bending and twisting, including (1) a device for twisting the cable in both left and right directions at the cable hanging point. (2) The lower end of the cable is fixed to a micro-bending device,
This micro-bending device must be mounted on a self-propelled large-bending vehicle. (3) The micro-bending device is provided with a mechanism (for example, a crank mechanism) for reciprocating motion on a large-bending self-propelled vehicle to apply micro-bends to the cable. (4) A self-propelled vehicle for large bending is equipped with a mechanism for reciprocating on an arc-shaped rail or rack, and applies large bends to the cable. A cable fatigue testing device characterized by having a mechanism.